During surgery, it may be necessary to temporarily mount an apparatus to exposed bone. For example, when using surgical navigation, it may be necessary to attach a tracker, such as a trackable reference array of optical markers, to the patient for accurately tracking the position of tools relative to the surgical site. If bone is the surgical target, such as when inserting a bone screw or the like, then attaching the reference array to bone provides better accuracy than attaching the reference array to surrounding soft tissues and more accurately tracks the position of the surgical tools relative to the bone. After the surgical procedure is completed (e.g., installing bone screws, rods, implants, and the like), the mounted tracker is typically removed.
Current methods for temporarily attaching trackers, reference arrays, or other devices to bone may include one or more of the following: screw-based mounting devices, in which one or more screws are inserted to hold the device to bone; clamp-based mounting devices, in which teeth and jaws of a clamp or clamps are tightened around bony prominences; or spike-based devices, in which one or more spikes are driven into bone with a mallet. These devices, however, may only provide for a single point of fixation to the bone, thereby providing a weak attachment to the bone and potentially compromising the accuracy of the tracker. In addition, traditional devices may be accidentally advanced too far into the bony structure, which can damage the bone or surrounding areas or make it difficult to remove the temporary mounting device, which is embedded too deeply into the bone, after the procedure is completed.